The present invention is directed to sharpening tools and in particular hand-held sharpening tools for sharpening ice skate blades.
Typically ice skate blades are sharpened by machining or grinding the blade edges on a milling machine or a grinding machine, respectively. Such machines may either be manually operated or computer operated. Whether manually or computer operated, such machines typically utilize jigs and guides to set the angle, arc and edges of the blades.
When ice skate blades need resharpening, one has had to usually have them resharpened at a sports shop, a skating rink pro shop, knife and scissors sharpening shop or a grinding shop catering to sporting equipment. In such instances the resharpening charges can amount to a considerable amount, and the sharpening job is not necessarily acceptable in quality. Such a sharpening job usually depends upon the care and skill of the operator. Moreover, the skate owner would have to relinquish the skates for a turn around time of up to a week.
It has been the object of the trade to develop a portable, and in particular, a hand-held sharpening tool for sharpening ice skate blades, which the skate owner could use. The problem with such prior art tools has been that they have been expensive to build, awkward to use or unreliable in the angle of the blade edges they produce, somewhat dangerous for an inexperienced user or they have been bulky to carry and not disposable.
Among the prior art is the skate sharpener of Krollius, U.S. Pat. No. 1,273,624. This sharpener has a cylindrical housing member in which a cylindrical honing stone is positioned. The cylindrical housing is grasped by the hand and drawn over the blade. Two guide blocks keep the blade sides in alignment with the honing stone. However, these guide blocks are located a considerable distance from the honing stone thereby permitting lateral movement of the blade with respect to the crown of the honing stone. Moreover, there is no control over the change in shape of the honing stone crown as the tool is used. The honing stone being of considerable bulk is intended to be used repeatedly. Both of these features lead to a degradation of the sharpening quality as the tool is used.
Corkum, U.S. Pat. No. 2,054,495, developed a sharpening tool which is more compact than the Krollius tool. Like Krollius, Corkum's tool uses but one honing stone and like Krollius, Corkum's tool is able to sharpen only the hollow concave surface in the bottom of the blade. The Corkum sharpener has a one piece cylindrical shaped housing holding a cylindrical or other shaped honing stone. Unlike Krollius, the Corkum tool has a separate handle extending away from the honing section of the tool. Like Krollius, the Corkum housing is of stamped steel. Corkum uses a separate steel guide section to align the blade with the honing stone. This guide section abuts the stone thereby eliminating the lateral movement permitted by Krollius, but causing either a scoring of the blade sides if the guide way is too tight or a wobbling of the stone as it is drawn over the skate blade. The Corkum hand grasping surface is elongate and cylindrically-shaped, as is Krollius, thereby being difficult to apply an even pressure over the longitudinal length of the stone/tool honing interface with the skate blade. This either promotes uneven sharpening or allows uneven sharpening to occur.
Nicolet, U.S. Pat. No. 2,118,617, introduced a hand-held skate sharpener with two different and separate sharpening guideways, one for the hollow of the blade and one for the blade side. The configuration of the Nicolet tool is such that the operator must hone the skate hollow in one operation and each of the blade sides in following successive second and third operations. Moreover, Nicolet does not provide a precise guide way for the hollow honing and no guideway whatsoever for blade side honing.
Toms, U.S. Pat. No. 2,900,769, introduced honing stone crown position adjustment to hand-held skate sharpener tools. Toms utilizes a solid rectangular block of aluminum or magnesium to hold a cylindrical or curved honing stone in a cylindrical longitudinal bore and incorporates an adjustment screw to adjust the position of the honing crown as the stone wears. Again, with Toms a reasonably bulky honing stone is incorporated for repeated sharpenings.
Kabriel, U.S. Pat. No. 3,585,880, departed from the art prior to his design by developing a hand-held tool which has a plastic housing. Two flat, rectangular honing stones are oriented orthogonally to one another to operate upon the bottom and one side of a skate blade at the same time. The tool housing has a slot into which a skate blade is inserted and into which the two honing stones extend. Kabriel does not concern himself with sharpening the hollow arc of the blade as did the previous art. He concerns himself only with sharpening/honing the corner or edge where the hollow and edge walls of a blade meet. His tool is able to sharpen only one of the two edges at a time. The blade must then be rotated and drawn through the tool to sharpen the second corner. Moreover, Kabriel's tool housing has a very flat or thin structure which allows a cocking or misalignment of the tool and its carried honing stones with the axis of the skate blade.
Larson, U.S. Pat. No. 4,815,240, shows a hand-held skate sharpener with a rectangular block housing similar to Toms. Like Nicolet, Larson utilizes two separate stones set into two separate guideways to sharpen the hollow and each of the two sides of a skate blade in a three step operation. Unlike Toms, Larson intentionally provides very wide guideways so that the skate blade can be shifted in the guideway to adjust the sharpening angle placed on the skate blade at the discretion of the operator. Larson's tool permits variations in sharpening position and tool usage and is intended for use by an expert operator.
Courchesne, U.S. Pat. No. 5,189,845, shows an extremely bulky, cumbersome and variably adjustable skate sharpening tool. With all of its adjustments, this tool concerns itself only with sharpening the hollow of the blade and provides an adjustment of stone position as did Toms. It is significant to note that it is apparently only Toms and Courchesne who recognize that honing pressure is a significant factor in obtaining a satisfactory sharpening and that even pressure over the length of the blade and laterally over the width of the blade is important.
Ellestad, U.S. Pat. No. 5,197,232, shows an elongate rectangular block housing which holds an arc shaped honing stone. Ellestad shows a screw adjustable guideway width. He has no adjustment on his honing stone position. As his honing stone bulk is substantial, the Ellestad tool is intended for repeated use without consideration to change in honing stone crown shape with use.
What is desirable is to provide an improved hand-held skate blade sharpening tool which is capable of sharpening the hollow of a skate blade and the two sides of the blade in one action.
What is also desirable is to provide an improved hand-held skate blade sharpening tool which is structured for an even application to the surfaces of the skate blade to be sharpened and which is disposable before the sharpening members of the tool deform from use.